This invention relates to a gravure printing machine, and in particular to a gravure printing machine for applying patterned striking compound stripes to pre-printed sheets to form finished matchbox skillets.
Conventionally, matchboxes are made by printing a plurality of rows of matchbox blanks on a continuous web of board, and then by applying stripes of striking compound to the blanks in a separate gravure printing operation. The gravure printing machine used in this process has the engraving roller positioned beneath the backing (or pressure) roller, so that the web is passed through the printing nip of the machine upside-down, that is to say with the pre-printed side facing down. After the web has left the gravure printing machine, the striking compound is dried in a radio frequency drier. As it is important that the striking compound does not touch any part of the drier, it is necessary to pass the web over a pair of reversing rollers prior to entering the drier, so that the printed surface of the web is uppermost when it enters the drier.
This conventional process is generally satisfactory, but it is only economical for long printing runs. For short printing runs, it would be much more economical to apply the stripes of striking compound to pre-printed sheets. Unfortunately, the known method would not be satisfactory for use with pre-printed sheets, as wet strips of striking compound would face downwards as the sheets leave the printing machine, and could not easily be turned over prior to entering the radio frequency drier.
The aim of the invention is to provide a gravure printing machine that can print stripes of striking compound material onto pre-printed sheets, and which can be used upstream of a radio frequency drier without having to re-orientate the sheets after they have left the printing machine.